The standard answer is: A, A, B, B, C, C, D, D, E, E stands for five pairs of twin brothers and sisters. First, consider (3). Suppose that A only participates in the activities of two groups and satisfies (1) and (2) at the same time. The two groups A participates in must be Abcde and ABCDE. Then continue to group. Take one person from D, E and B, C, D and E (non-twin relationship), and pair them with A to form four groups of Bac, Cab, Dae and Ead to ensure the minimum K. Finally, group the remaining two people who are not in the same group, namely Bd, Be, Cd, Ce, d b, Dc, Eb, Ec, *. Therefore, the minimum value of K that meets the requirements is 14. The answer is n= 1 1. Because I need to draw pictures, I make photos of my answers. Click here/xiaozhaotaitai/album/item/4f92e6ee5cd184392cf534c2.html.